The Titanic didn't have them. Neither did the snooty Queen Elizabeth 2 or the swinging TV Love Boat Pacific Princess.

But now many travellers refuse to cruise if they don't have a balcony cabin.

"The first couple times I cruised I had a porthole window, but the third time I went to the balcony room, and I never went back after that," says Peggy Earo of North Carolina, who on this cruise has a balcony cabin on Deck 2 not far above the ocean swells.

"It's a sense of airiness. It's very calming and soothing. I like to see the storms and the waves, the sunrise and the sunset.

"I would not come without the balcony. It's that important to me."

Earo isn't alone.

And the cruise industry has taken notice.

Eighty per cent of cabins on the new Regal Princess ship debuting in May will have balconies. Sleek new river-cruise lines are inventing ways to give guests true balconies instead of just a railing. And big cruise lines keep making their balcony (also called veranda) cabins ever more elaborate.

"I would never book an inside stateroom," says John Safranski of Michigan, who has taken 10 cruises and has an 11th already booked. "It doesn't get much better than sipping champagne out on the balcony as we cruise into the sunset."

Balcony cabins cost about 25 per cent more than inside cabins. But that is less of a price difference than a few years ago.

"Back in the day it could have been 75 per cent to 100 per cent more expensive to get a balcony, there were so few of them," says cruise analyst Stewart Chiron of Miami-based the Cruise Guy.

These days, "it would be crazy to build a ship that doesn't have them ... Without a doubt they are the most popular cabins on a cruise."

He says what is going away are "ocean-view" cabins - cabins that have window views of the water, but no way to sit outside.

And even inside cabins these days are being tricked out with "virtual balconies". The new Royal Caribbean Quantum of the Seas class of ships debuting in November will have soothing video of the ocean broadcast on an interior wall, giving the feel of a balcony cabin if not the bracing reality.

Not that long ago, cruise-ship balcony cabins were for the few and the affluent, if ships offered them at all.

Royal Caribbean's Monarch of the Seas was considered one of the first truly modern cruise ships in 1991. It offered balconies for five per cent of its cabins, and that was a big deal. Ships built in the 2000s offered about 25 per cent to 45 per cent balcony cabins.

Now, all new ships offer balconies on more than 65 per cent of rooms.

And the price differential is shrinking.

The Detroit Free Press looked at prices on seven cruise lines and ships for a typical seven-day Caribbean cruise in November. We found a price premium of 18 per cent-34 per cent over an inside cabin - but deals to be had, such as an US$849 (NZ$995) balcony cabin price on the new Regal Princess, just US$150 more than an interior cabin.